Combustion chamber construction



Feb. 16, 1932.

COHBUSTION CHAMBER CONSTRUCTION Filed Aug. 29. 1930 ,4V ATTORNEYS A. MooRE l 1,845,982

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Patented Feb. 16, 1932 r STATES PATENT oFFlcE Ml'dllibrfllll td'illtE, Gl? NEW' YRK, N. Y., ASSIGNR, BY )RESINE ASSIGNMENTS, T0 MX GRPSALMMN, 0l? NEW YORK, N. lif., .d CURPMTION 0F DELAWARE COMBUSTON MIETEN CDNSTRUGTUN' application nea august aa, ieee.. semi nu. tracer.

lilly invention relates to combustion cham'- ber constructions for internal combustion engines, and particularly tor aviation or valve-in-head engines, employing multiple ignition, and the same has for its object to provide a construction which reduced detonation or knocking by physically controlling the heat and Haine propagation to prevent the development ot auto-ignition temperatures and pressures.

Another object out the invention is to provide a construction ot the character specilied in which a combustion chamber ot a predetermined clearance volume is relatively reduced. at the part thereoi' contiguous to the valves9 and compensation in volume obtained by 'forming an abrupt enlargement in said part in oilsset relation to the valves serving to also cause expansion of the dame Wave propagated through the combustion chamber.

.another object ot the invention is to pro vide a construction ot the character speci tied capable oit simultaneously controlling the flame propagation 'from tvvo or more ig nition points tor reducing or preventing detonation.

Another object ot' the invention is to provide a construction oli the character speci `fied in which the space available for thus controlling` 'llame propagation originating at separated points is substantially conned to that above the piston.

llligure 1 is a sectional elevation of one torni ot combustion chamber construct/ed ac-` cordingr to and embodying my said invention; and

2 is a plan ot' the piston.

llhe invention relates to combustion cham'- her constructions in which detonating pressures are prevented by causing the flame to expand as the same is propagated, the invention residing particularly in the application of this principle to valve-in-liead engines f with multiple ignition.

Referring to the drawings, the engine 10 is of the valve-inhead form, such as that adapted for aviation, either of the radial or straight line type, one cylinder 12 of the several usually employed being illustrated.

rlhe cylinder bore 14 With the piston 16 Working therein is closed by a cylinder head 18, the tvvo portions forming a combustion chamber 20 above the piston 16. The head I 18 is formed `with a passage 22 controlled by the inlet valve 24 tor the delivery of the charge mixture into the cylinder and with a passage 26 controlled by exhaust valve 28 tor the discharge ot the exhaust gases from the cylinder.

rllhe combustion chamber 20 in the top dead center position of the piston is substantially cross-shaped in configuration and includes a horizontal cylindrical portion 20n intermediate the piston 16 and the head 18 and the 'transverse medial portions 20b and 20c comniunicating therewith in a medial pla-ne and located respectively in the piston 16 and in the cylinder head 18.

'lhe portions 2Gb and 20 are preferably semicylindrical in shape, providing recesses of substantially uniform Width and having elongated openings or mouths 32 of ample size to prevent the trapping of the exhaust gases in the recesses and thereby preventing good scavenging.

The portion 2()a has a diameter which is substantially equal to the diameter of the pis ton and a depth, in the top dead center position ot the piston, which provides minimum clearance in allowing full opening movement A ot the valves 24 and 28.

rlhe portion orl recess 20c is located between the valves 24 and 28.

Spark plugs 32 and 34 are received in the cylinder 12 at diametrically opposite points between the valves 24 and 28 and the piston 16 in the top dead center position thereof, and preferably lie on a line at right angles to the plane of the medial portions 20"- stroke are propagated from the ignition4 'means 32 and 34: through the combustion valves and the piston in `vent or reduce chamber portion 20a. The flame acceleration is initially rapid, without expansion, for a distance a little less than one-half the diameter of the piston and thereupon the wave fronts expand into the spaces 20h-20 to predetonation. By utilizing two spark plugs, the distance traveled by the ame is comparatively short for the clearance volume. i K

In my invention the space 20 between the which the flame waves are initially propagated is confined in ldepth to that necessary for proper valve opening irrespective of the total clearance volume (or compression ratio) of the combustion" chamber, the remaining space necessary for obtaining a given clearance volume being formed as the expansion spaces 20b or 20?, or both. That is to say, for a given clearance volume, in the absence of the portions 20b and 20,the depth of the portion 20* would have to be greater. By my invention, therefore, the desired clearance volume is while providing expansion spaces ing detonation.

The clearance volume, and hence the compression ratio, can be varied to obtain'that which is most suitable for the purpose by change in the volume of the recesses 20?; or 20 only without edecting any change in top dead center position of the piston or otherwise varying the depth ofthe part 20a.

The combustion chamber 20 is ldisposed symmetrically relative to or equally at opposite sides of the line oining the spark plugs 32 and 34, and lies entirely within a circle having said line as a diameter. Good results in reducing detonation, while operating with relatively high compression ratios, can be obtained if the recesses 2Gb-20, while lying wholly within said circle, form conjointly an expansion space 20"- P of a length transversely of the direction of flame propagation which is as great as or greater than the distance traveled by the iame, i. e., a distance substantially equal to one half the diameter of the piston,

It is a characteristic of my invention that While small clearance volumes or high compression ratio may be employed, nevertheless, with the small space available, detonation is effectively reduced by expansion of the flame fronts.

The incoming charge passing the valve 24 into the cylinder and the exhaust gas passing the valve 28 'from the cylinder have unobstructed passage. Greater radiation of heat through the piston head 'and cylinder head is effected because the surface thereof is of eater area than flat surfaces would be.

urther, less space is required in the cylin'ld'er for reducobtained head for a combustion chamber of a given com ression ratio.

ith the combustion it is possible to operate internal combustion engines with gasoline instead of benzol blends, and to use fuels heavier than gasoline without causing detonation. i

Having thus described my invention, what l claim and desire to secure by Letters Patent is:

i. n an internal combustion engine, portions forming a combustion chamber, intake and exhaust valves therein, said combustion chamber including a part contiguous tothe valves having a clearance approaching the minimum required for allowing full opening movement of said valves,

and a part in ofiset relation to said valves forming an enlargement of said first named part and having a volume compensating for therestriction in volume of said first named part to provide a combustion chamber of predetermined clearance volume equal to the combined volumes of said parts, and ignition means in said first namedpart locatedto propagate the inflammation towards the enlarged porchamber thus formed n tion, whereby to cause expansion ofthe flame n pave thereinto forreducing detonation efects.

2. In an internal combustion engine, portions forming a combustion chamber, and exhaust valves therein, said combustion chamber including a part of uniform depth contiguous tothe valv'\es having a clearance approaching the minimum required for allowing full opening movement of said valves,

, and a part in off-set relation to said valves forming an abrupt enlargement of said first named part and having a volume compensating for the restriction in volume of said first named part .to provide a combustion `chamber of predetermined clearance volume equal to thegcombined volumes of said parts, and ignition means in the first named part located at a point remote from the enlarged portion, whereby to propagate the inflammation initially'through the part of uniform ldepth and then suddenly expand the flame wave front at the enlarged portion for reducinlg detonation effects.

an internal combustion engine, portions forming a combustion chamber, intake therein, said combustmn and exhaust valves chamber including a part providing clearance approaching the minimum required for allowing full opening movement of theA intake and exhaust valves, and a part in ofi-set relation to said valves forming an enlargement of said first named part, said parts conjointly forming a combustion chambenof predetermined compression ratio, and ignition means in said first named part located to propagate the flame towards the enlarged ortion for causing expansion of the wave ront to reduce detouation.

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4. lin an internal combustion engine, portions forming a combustion chamber substantially cross-shaped in cross-section.y

5. ln an internal combustion engine, p0rtions forming a combustion chamber of suhstantialiy cross-shaped formation, and spark plugs in one ot' the combustion chamber parts at opposite sides ot the part disposed transversely thereto.

6. ln an internal combustion engine, portions forming a combustion chamber including a reduced part and parts extending symmetrically from opposite sides thereof at a given point to torna an enlarged space, and ignition means disposed in said reduced part at a point remote from the enlarged space.

7. ln an internal combustion engine, portions 'forming a combustion chamber having an intermediate abrupt enlargement, and ignition means therein at opposite sides of said enlargement.

8. ln an internal combustion engine, portions forming a combustion chamber having an intermediate abrupt enlargement. intake and exhaust valves disposed at opposite sides ot said enlargement, and spark plugs therein .at opposite sides ot said enlargement and said valves.

9. ln an internal combustion engine, portions forming a combustion chamber., intake and exhaust valves opening into said combustion chamber. said combustion chamber having parts contiguous to said valves of suhstantially uniform depth and a part intermediate said ralvestorming an enlargement oi: the tiret named part, and spark plugs in said first named parts at points remote 'from said enlargement.

l0. ln an internal combustion engine, portions 'forming a combustion chamber having a reduced part and a relatively enlarged part, and ignition means in the reduced part, said enlarged part having a length transversely of the direction of flame propagation at least substantially as great as the distance ot dame travel thereto from `aid ignition means.

ll. ln an internal combustion engine, portions forming a combustion chamber hav-ing a reduced part and a relatively enlarged part extending symmetrically at opposite sides ot the reduced part, and ignition means in the reduced part at a point remote from the enlarged part, said enlarged part having a length transversely oi" the direction ot Haine propagation substantially greater than thc distance ot tlame travel thereto from said ignition means.

l2. ln an internal combustion engine, portions forming a combustion chamber having a reduced part and an intermediate relatively abrupt enlargement, and ignition means disposed in said reduced part at opposite sides ot said enlargement, said enlargement having a length transversely of the reduced part at least substantially as great'as the distance of travel of the flame thereto from either ignition means.

13. In an internal combustion engine, portions forming a combustion chamber having a reduced part contiguous to the valves of vsubstantially uniform depth and relatively enlarged parts extending outwardly at opposite sides of said reduced part at the center thereof, said parts'having volumes-conjointly giving a combustion chamber of predetermined clearance volume, and ignition means in said reduced part at opposite sides of the intermediate partshsaid intermediate parts havinga total length transversely ol said reduced part at least substantially as great as the distance of flame travel thereto from either ignition means.

ld. ln an internal combustion engine, a cylinder, a cylinder head therefor anda piston, said head and said piston in the top dead center of the piston forming a combustion chamber having a maximum dimension substantially equal to the diameter of the 'piston, and having a relatively abrupt enlargement, and ignition means in said combustion chamber at a point remote from said enlargement.

15. ln an internal combustion engine, a cylinder, a cylinder head therefor and a piston, said head and said piston forming a substantially cross-shaped combustion chamber, and ignition means at diametrically opposite points ot said combustion chamber.

16. ln an internal combustion engine, a cylinder, a cylinder head therefor and a piston, said head and said piston forming a combustion chamber including a reduced part ot" substantially uniform depth having a maximum dimension substantially equalA to the diameter of the piston, and a part extending transversely thereto and substantially bisecting said lirst named part, and spark plugs located in said reduced part at opposite sides of the transverse part.

17. In an internal combustion engine, a cylinder, a cylinder head therefor and a piston, said head and said piston forming therebetween a combustion chamber of relatively reduced depth and having recesses therein forming an intermediate enlargement of the combustion chamber, and ignition means at opposite sides ot said enlargement. I

18. ln an internal combustion engine, a cylinder, a cylinder head therefor, a piston, and intake and exhaust valves in said cylinder head, said cylinder head and said piston forming a combustion chamber including a reduced part of substantially uniform depth contiguous to said valves, and having recesses therein having elongated and relatively Wide mouths and forming a symmetrical enlargement of said reduced part extending transversely thereof diametrically ot' the piston between said valves, said combus- Miti tion chamber parts having volumes conjointly forming a 'combustion chamber of predetermined compression ratio, yand ignition means in the reduced part of said com- 5 bustion chamber at opposite sides of said enlargement, said enlargement forming an expansion space having a length transverse- 1y of the direction of flame propagation at least substantially equal to the distance of {iame travel from either ignition means.

In testimony whereof, have signed my name hereto.

ARLXNGTQN MOORE. 

